Locating the sources of water leakage in existing building facades is challenging, time-consuming, and an ongoing annoyance to building owners. This paper proposes adaptation of existing testing methods to increase the effectiveness of testing for many of these issues. The method utilizes Positive Pressure Ventilation (PPV) fans, paired with a modified AAMA 501.1 (AAMA 501.1-05: Standard Test Method for Water Penetration of Windows, Curtain Walls and Doors Using Dynamic Pressure, 7, AMAA, Schaumburg, IL). test procedure, to present a cost effective, versatile, time-saving and realistic means of replicating weather events to recreate leaks in architectural facades. PPVs eliminate the need for interior test chambers, reduce setup costs, and allow for the testing of walls where conventional test chambers cannot be practically constructed. This approach applies a regulated wind source and calibrated spray rack to simulate a given wind/rain event. This paper demonstrates a procedure of utilizing up to 8 PPV fans, generating wind speeds ranging from 0–60 mph, and when combined with a calibrated spray rack, is capable of simulating realistic wind-driven rain conditions onsite. Employing this method, we have had a 100 % success rate in locating known leaks on existing buildings. This method has been proven to recreate leaks without overloading the building’s water management systems through unrealistic wind pressures or excessive water injection that exceed what the facade experiences under realistic conditions. The ease of set up, flexibility, and the capability to control the start and stop of the leaks, makes this testing procedure a valuable tool for the forensic leak investigator. The authors look forward to other investigators improvements to our methods; and help to encourage ASTM to consider developing a new standard for its use.